Agriculture faces numerous challenges that are making it increasingly difficult to provide food, materials, and fuels to the world's population. Population growth and changes in diet associated with rising incomes are increasing global food demand, while many key resources for agriculture are becoming increasingly scarce. By 2050, the FAO projects that total food production must increase by 70% to meet the needs of the growing population, a challenge that is exacerbated by numerous factors, including diminishing freshwater resources, increasing competition for arable land, rising energy prices, increasing input costs, and the likely need for crops to adapt to the pressures of a more extreme global climate. The need to grow nearly twice as much food in more uncertain climates is driving a critical need for new innovations.
Today, crop performance is optimized via of technologies directed towards the interplay between crop genotype (e.g., plant breeding, genetically-modified (GM) crops) and its surrounding environment (e.g., fertilizer, synthetic herbicides, pesticides). While these paradigms have assisted in doubling global food production in the past fifty years, yield growth rates have stalled in many major crops and shifts in the climate have been linked to production declines in important crops such as wheat. In addition to their long development and regulatory timelines, public fears of GM-crops and synthetic chemicals has challenged their use in many key crops and countries, resulting in a complete lack of acceptance for GM traits in wheat and the exclusion of GM crops and many synthetic chemistries from European markets. Thus, there is a significant need for innovative, effective, and publically-acceptable approaches to improving the intrinsic yield and resilience of crops to severe stresses.
Like humans, which benefit from a complement of beneficial microbial symbionts, plants have been purported to benefit somewhat from the vast array of bacteria and fungi that live both within and around their tissues to support their health and growth. Endophytes are fungal or bacterial organisms that live within plants. Bacterial and fungal endophytes appear to inhabit various host plant tissues and have been isolated from plant leaves, stems, or roots.
A small number of these symbiotic endophyte-host relationships have been purported in limited studies to provide agronomic benefits to model host plants within controlled laboratory settings, such as enhancement of biomass production (i.e., yield) and nutrition, increased tolerance to stress such as drought, and/or pests. Yet, such endophytes have been demonstrated to be ineffective in conferring benefits to a variety of agriculturally-important plants; as such, they do not adequately address the need to provide improved yield and tolerance to environmental stresses present in many agricultural situations for such crops.
Thus, there is a need for compositions and methods of providing agricultural crops with improved yield and resistance to various environmental stresses. Provided herein are novel compositions of bacterial and fungal endophytes and synthetic endophyte-plant compositions based on the analysis of the key properties that enhance the utility and commercialization of an endophytic composition.